# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals
import urllib.parse
import json
from .custom import CustomHeaders
from scrapy.http.headers import Headers

# useful for handling different item types with a single interface
from itemadapter import ItemAdapter

HMACCOUNT_SESSIONID_ = {
    "Hm_lvt_0d2227abf9548feda3b9cb6fddee26c0": "1762152126,1762493820",
    "HMACCOUNT": '032BDB7179F4E0E2',
    "sessionid": '3uxcdhn5dyypc3grvx0rn6qfgbkikc0i',
    "Hm_lpvt_0d2227abf9548feda3b9cb6fddee26c0": "1762567327"


}


class MashangpaSpiderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, or item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Request or item objects.
        pass

    async def process_start(self, start):
        # Called with an async iterator over the spider start() method or the
        # maching method of an earlier spider middleware.
        async for item_or_request in start:
            yield item_or_request

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)


class MashangpaDownloaderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.

        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)

class GlobalCookieMiddleware:
    def process_request(self, request, spider):
        global_cookies = HMACCOUNT_SESSIONID_
        request.cookies.update(global_cookies)
        if spider.parser.Cookies:
            request.cookies.update(spider.parser.Cookies)

        add_headers = spider.parser.Headers
        if add_headers:
            #自定义Header，处理header默认转首字母大写问题
            custom_headers = CustomHeaders()
            custom_headers.update_for_Headers(request.headers)
            custom_headers.not_normkey_update(add_headers)
            request.headers = custom_headers
        #在headers添加referer，第二题会校验
        request.headers['referer'] = spider.start_url

        if request.method == "GET":
            params = json.loads(request.body)
            query_string = urllib.parse.urlencode(params)
            url = request.url+ "?" + query_string
            request._set_url(url)
        # request.headers['accept'] = "*/*"
        # request.headers['sec-fetch-dest'] = "empty"
        # request.headers['sec-fetch-mode'] = "cors"
        # request.headers['sec-fetch-site'] = "same-origin"
